With development of communications technologies, there comes into being different systems, such as a synchronous digital hierarchy (SDH), an optical transport network (OTN), a common public radio interface (CPRI), and the Ethernet. In a metropolitan area network, service requirements are complex, and generally, various devices compete with each other and complement each other. Consequently, multiple sets of devices run concurrently or in parallel in the metropolitan area network. For example, even in a room, there is one set of SDH devices, one set of OTN devices, one set of Ethernet switches or routers, and other grouping devices. Multiple links are configured correspondingly. However, resource utilization of the devices and the links is not high and is generally around 30% or below, and the multiple sets of devices occupy relatively much room space. Therefore, relatively large power consumption is caused, and multiple groups of staff are required for maintenance and management. This has become a priority problem that needs to be considered and resolved in the metropolitan area network.